I created a Main Net 2-3 Multi Signatur Wallet with Blue Wallet and tried to export the Multi Signatur Wallet Deskriptor to the Specter DIY.

It was not possible as Specter seems to currently not support the Format Blue Wallet is using.

Here is the Wallet Deskriptor I tried to import into the Specter:
TestmultiSigGitHubIssue.txt

Here the Transaktion as QR-Code (I used: GM65, SW 105, Specter Firmware v1.10.3)